Cylinder for two-stroke internal-combustion engines with scavenging ports



Oct. 1

18 927 H. BECKER CYLINDER Fox Two-STROKE INTERNAL coMBusTIoN ENGINESWITH scAyENGING Po'nI's Filed Sept. 5. 1925 D mm Patented Oct. 18,1927".

UNITED STATES 1,545,515 PATENT oEFicE.. l

HEINRICH BECKER, F KIEL-HASSEE, GERMANY, ASSIGNOR T0 FRIED. KBUPP GER-HANIAWERFT AKTIENGESELLSCHAFT, 0F KIEL-GAARDEN, GERMANY.

CYLINDER FOB TWO-STROKE INTERNAL-COMBUSTION ENGINES WITH SCAVENGINGPORTS.

Application led September 8, 1925, Serial No. 541,331, and in GermanySeptember 13, 1924.

This invention relates to a cylinder for two-stroke internal combustionengines with scavenging ports. In engines of this type the istons mustbe made very long because I the inlet andoutlet ports controlled by thepiston have to be covered. by` the piston durin the whole piston stroke.Therefore the cy inders, especially those of double-acting engines, mustalso be made of a great length.`

For large units the cylinder castings will therefore become so largethat serious difficulties arise in the manufacture of the same. Theinvention has for its object to avoid the said disadvantage, this beingattained by making the cylinder body of a middle piece taking up theforces and containing the channels for the admission of the air and byproviding in single-acting engines a cylinder jacket formed as -a simplepipe-like member, while double-acting engines are provided with twocylinder jackets of the ind stated.

Several embodiments of the subject-matter ofthe invention areillustrated in the accompanyin drawin in which:

Fig. 1 is a ongitudinal section through a cylinder of a single-actingmulticylinder two-stroke engine,

Fi 2 is a longitudinal section through 3o a c y inder of a double-actingtwo-stroke engine, f l

Fig. 3 is a cross section along the line 3-3 ofthe Figs. 1 and 2 andFig. 4 is a. view, similar to Fig. 2, of the lower portion of a somewhatmodified form.

The embodiment according to Fig. 1 will bev described first. i

Each cylinder consists of a cast. middle P piece A supported bystandards E as well 40 as of a cylinder jacket B formed as a sim- A plepiece of pipe and of the liner C and the cover D. The middle pieces A ofthe several cylinders lie against each other by lateral packing faces a1and are fixed oneto the other so that the engine forms a rigidstruct-ure. Chambers for the admission of the scavenging air and fortheloutlet of the exhaust gases are formed by partitions a? and a1 (seeparticularly Fi 3) which are provided in the interior of t e 'middlepiece A and surround the outer space which com-- municates with theinterior of the liner through the inlet and outlet ports c, of rovidedin I,the same. The remaimng ho low space of the middle piece is designedto be I illed with cooling water. The cylinder jacket B mounted on themiddle iece is fastened-to the latter by means of ong screws F whichserve at the same time to hold the cover D. The liner C is inserted intothe cylinder jacket from above and engages by vmeans of a flange 01acorresponding turnedo ut groove of the cylinder jacket B; it is, tightlypressed against the cylinderjacket B by the cover D, the flange c1serving as a packing. The liner C is only centered in the middle part ofthe middle piece A while, for. the rest, it has lateral play'. Thereremains, more particularly, an annular passage a* at the place wheretheliiier enters into the middle piece, so that the cooling-l water roomof the middle piece is in communication with the narrow cooling-waterroom b3 formed between the liner and the cylinder jacket B.

vIn case of a very great stroke it may be preferable to center the liner'also in the u ger and lower wall of the middle piece pecial bores havethen to be made for the circulation of the cooling water.

The cylinder according to Fig.`2 which is ldesigned to be used in adouble-acting engine is providedV with two pipe-like cylinder jackets B1and B1, one above and the other below the middle piece A. In this case,the liner is divided below the centre along an undiilatory line, its twoparts C1 and C2 being inserted into the cylinder jackets from above andbelow, respectively. The two rows of ports ca (Fig. and c* for the upperand the lowerv cylinder half are disosed in the upper part C1 of theliner.

With the described cylinders the middle cylinder piece, which containsthe inlet and outlet .channels and which is therefore always diicult tomanufacture, so that itl may be cast easily. The cylinder 'ackets B andB1, B1, respectively, produced is very short y the sub-division aresimple pipe-like members which are likewise simple to manu- .facture andrelieved of tensile forces. They may therefore be made thin-walled andlight. Besides, there may be readily. formed between the cylinder jacketand the liner a narrow space for the circulation therethrough of coolingwater, so that a good cooling action is attained especially at thehottest part of the cylinder. -A's moreover',

Ithe liners are only centered in the middle portion of the cylinder itis very simple to finish and insert them. A special advantage of thedescribed construction still resides lin that the cylinders may bealtered in a very simple manner for a higher 'output by lengthening thepipe-like liners and cylinder jackets without it being necessary tochange the middle pieces.

Instead of placing themiddle pieces A directly on the standards E,'-theymay be provided with feet cast ,integrally with them, (see particularlyFig. 4), in lwhich case the standards can be made of a correspondinglylower height. l

Claims:

1. A cylinder for two-stroke internal combustion engines comprising aliner, scavenging ports in said liner, a jacket surrounding a part` ofsaid liner including the scavenging ports, comprising an outer casingand an inner annular flange closely surrounding said liner and leavingspace for water between the outer casing and the inner flange, inlet andoutlet channels in said inner ,flange opposite said ports, ,a flangedpipe member surrounding the remainder of said liner and having one endabuttin against the outer casing and the other agalnst the correspondingend of the liner, a cylinder head covering the abutting ends of theliner and flanged pipe, and'closing the end of the liner, and boltspassing through the cylinder head, the anges of the flanged pipe, andthe end of the outer casing for clamping said parts together, theflanged pipe, and the end of( the outer casing adjacent thereto beingspaced from the liner to permit flou of water therebetween. v

.2. A cylinder for two-stroke internal combustion engines, comprising aliner, scavenging ports in said liner, a sleeve fitting closef ly arounda portion of said liner including said ports and adapted to withstandthe engine forces, inle and outlet channels in said sleeve opposiie saidports, an outer casing surrounding said sleeve and forming a space forcooling liquid, a flanged pipe member surrounding the remainder of saidliner and abutting at one end against said casing and at the otheragainst the end cf said liner, and a cylinder head -clamped againts theabutting ends of said liner and flanged pipe and closing the end oftheliner.

The foregoing specication signed at Hamburg, Germany, this eighth day ofAugust, 1925.

HEINRICH BECKER.

